Improvement in tool-holders



i shown in the drawing.

UNITED STATES PATENT OFFICE.,

NELSON I. BRADISH, OF JERSEYVILLE, ILLINOIS.

IMPROVEMENT IN TOOL-HOLDERS.

Specification forming part of Lettere Patent No. 147,894, dated February 24, 1874; application tiled March 29, 1873.

To all whom t may concern:

Be it known that I, NELsoN P. BRADIsE, of J erseyville, in the county of Jersey and State of Illinois, have invented a new and Improved Tool-Holder; and I do hereby declare that the following is a full and exact description of the same, reference being had to the accompanying drawings and to the letters of reference marked thereon.

llhe object of the invention herein described is to provide a light, cheap, and substantial instrument for holding edge-tools upon the grindstone while being sharpened; and is so constructed as to be available for use upon the rest of any ordinary grindstone, enabling the most unsteady and unskilled hand to produce a true and uniform edge, of any required angle, more expeditiously and with greater ease than when held by the hand of the most expert operator.

In the drawing, A Al represents two metal bars, secured near their middle, at a suitable distance apart, by a cross-plate, B, the lower extremities of A Al being brought "together, welded, and rounded down to a point, l?, as Between the upper extremities of these bars is riveted a handle, H, preferably made of wood. C is a clampplate, operated by two screws and thumb-nuts, o c. To the outside of the bars A A are pivoted two small clamp-plates, d d', operated by screws and thumb-nuts, e e. The clamp-plate O is designed to hold such tools as plane-bits, chisels, Sto., the small clamp-plates d d to hold draw-knives.

The instrument is used somewhat as follows To grind a plane-bit or chisel, the tool is firmly secured in the required position upon the plate B by means of the clamp-plate C; then,taking i ing the lower extremity of the instrument, is

placed upon the rest of the grindstone at such a distance from the face of the stone as to give to the cutting-edge the required angle; then, by gently pressing forward and downward, the tool is made toimpinge upon the face of the stone with a degree of intensity proportionate to the pressure applied. For grinding a draw-knife, the shanks of the latter are secured by the clamp-plates d d', and the operation is similar to that just described. It will be observed that the construction of this instrument is such as to admit of the tool being removed from the face of the stone and turned toward the operator for examination, without necessitating the removal of the point P from its seat in the rest of the grindstone, thus preserving the relative angle of the tool to the face of the stone. Further, the instrument, resting upon a single point, readily admits of adjustment to any required position, and of that lateral rocking motion essential to the uniform wear of the stone.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The tool-holder described, having the side piecesA A terminating in point P, side clamps d d', and cross-bar B, with olamping-plateG, as described, the bar B being relatively so arranged to the side piece that the holder is adapted to be used in front of the grindstonc, as shown and described.

This specification signed and witnessed this 22d day of March, 1873.

NELSON P. BItAlDISH. 

